books.google.com - Elastic filaments refer mainly to titin, the largest of all known proteins. Titin was discovered initially in muscle cells, where it interconnects the thick filament with the Z-line. Titin forms a molecular spring that is responsible for maintaining the structural integrity of contracting muscle, ensuring...https://books.google.com/books/about/Elastic_Filaments_of_the_Cell.html?id=sdYl5sxM1sMC&q=titin+isoforms&utm_source=gb-gplus-shareElastic Filaments of the Cell